Commercial fishermen in the Gulf of Mexico are catching endangered loggerhead sea turtles at an alarming rate, according to a new federal report.
Protected by federal law, the turtles are drowning when they get hooked on longlines, sometimes extending a mile or more along the ocean floor.
"The numbers are pretty alarming," said Tom Wheatley of the Marine Fish Conservation Network. "This is definitely an issue that will require action."
Most of the grouper landed in Florida are caught by boats that lay miles of monofilament fishing line, baited with thousands of hooks, across the sea bottom. This fishing method is effective but controversial.
Recreational anglers and conservationists charge that bottom longlines kill indiscriminately, catching everything from undersized grouper to protected species such as loggerhead sea turtles.
Until now, there was little data to support those charges, typically disputed by longliners.
But beginning in 2006, the National Marine Fisheries Service began placing official observers aboard longline vessels used in fishing for sharks and grouper.
During the study, which lasted a year and a half, federal observers went along on 34 fishing trips and documented 18 hooked sea turtles. Some of the turtles were dead, some comatose and some alive but injured.
Based on these numbers, federal officials estimate that each year, about 974 sea turtles are caught on longlines. Of those, 433 were released alive, 325 were released dead or unresponsive, and the remaining 216, were listed as unknown.
The results of this report, compiled by the fisheries service's Southeast Fisheries Science Center in Miami, will be presented to the Gulf of Mexico Fishery Management Council when it meets this week in Mobile, Ala.
"This is a serious issue," said Dr. Roy Crabtree, administrator for the service's Southeast Region. "We will have to determine if this is going to have an impact on the continued existence of the loggerhead sea turtle."
David L. Allison, as senior campaign director for the environmental group Oceana, has asked Thomas McIlwain, the gulf council's chairman, to take immediate action.
"The newly available observer data from the fleet reveals that virtually one out of every two longline sets has at least one loggerhead sea turtle take, and furthermore, the mortality level of these takes may be equal to or greater than 50 percent," Allison wrote in a letter dated Oct. 13. "The estimated longline takes are nearly 8 times the level authorized."
The federal report comes at a particularly sensitive time for loggerhead sea turtle populations. The species suffered greatly in the 1980s, when more than 10,000 sea turtles were killed each year in shrimp trawls. The federal government eventually required the shrimp industry to begin using "turtle excluder devices" that eventually cut down on mortality.
About 90 percent of the world's loggerhead sea turtles nest on Florida's beaches. But in recent years, the number of documented sea turtle nests has steadily declined.
The final numbers for the 2008 nesting season will not be ready until December, said Blair Witherington, a biologist with Florida Fish and Wildlife Conservation Commission. But preliminary data shows the number of nests may have increased from 2007, one of the worst years in more than a decade.
Witherington bases this on reports from 33 beach sites, which account for 72 percent of the state's nesting sea turtles.
Last year, those sites reported 28,073 nests, compared with 38,643 this year.
"The numbers zig and zag a little, but in general, they have been going down" since 1998's peak of 59,918, Witherington said.
Conservationists blame many factors, including development and Red Tide, for the downward trend. But now, many believe longlines may be contributing to this decline.
"Longlines are adding to the problem," Witherington added. "The number of loggerhead sea turtles killed in fisheries is significant enough to affect population trends, and lo and behold, we are seeing declining numbers of sea turtle nests. It is a smoking gun, and we have a dead body."
Bob Spaeth, a commercial fishing boat owner who often represents his industry in dealings with the federal government, said he was surprised by the extent of the problem.
"We don't know why all of a sudden we are seeing all of these sea turtles on our lines," he said. "But we need to find a solution. Nobody wants to be out there killing sea turtles."